org.apache.oro.text
public interface PatternCache
A PatternCache is an object that takes care of compiling, storing, and retrieving regular expressions so that the programmer does not have to explicitly manage these operation himself. The main benefit derived is the ease of use from only having to express regular expressions by their String representations.
Since: 1.0
Version: 2.0.8
See Also: MalformedCachePatternException
Method Summary | |
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Pattern | addPattern(String expression)
Adds a pattern to the cache and returns the compiled pattern. |
Pattern | addPattern(String expression, int options)
Adds a pattern to the cache and returns the compiled pattern. |
int | capacity()
Returns the maximum number of patterns that can be cached at one time.
|
Pattern | getPattern(String expression)
This method fetches a pattern from the cache. |
Pattern | getPattern(String expression, int options)
This method fetches a pattern from the cache. |
int | size()
Returns the number of elements in the cache, not to be confused with
the capacity which returns the number
of elements that can be held in the cache at one time.
|
addPattern() is meant to be used when you expressly intend to add an expression to a cache and is useful for front-loading a cache with expressions before use. If the expression added does not already exist in the cache, it is compiled, added to the cache, and returned. If the compiled expression is already in the cache, it is simply returned.
The expected behavior of this method should be to start replacing patterns in the cache only after the cache has been filled to capacity.
Parameters: expression The regular expression to add to the cache.
Returns: The Pattern corresponding to the String representation of the regular expression.
Throws: MalformedPatternException If there is an error in compiling the regular expression.
addPattern() is meant to be used when you expressly intend to add an expression to the cache and is useful for front-loading a cache with expressions before use. If the expression added does not already exist in the cache, it is compiled, added to the cache, and returned. If the compiled expression is already in the cache, it is simply returned.
The expected behavior of this method should be to start replacing patterns in the cache only after the cache has been filled to capacity.
Parameters: expression The regular expression to add to the cache. options The compilation options to use when compiling the expression.
Returns: The Pattern corresponding to the String representation of the regular expression.
Throws: MalformedPatternException If there is an error in compiling the regular expression.
Returns: The maximum number of patterns that can be cached at one time.
addPattern()
except that it doesn't
throw a MalformedPatternException. If the pattern is not in the
cache, it is compiled, placed in the cache, and returned. If
the pattern cannot be compiled successfully, the implementation must
throw an exception derived from MalformedCachePatternException.
Note that this exception is derived from RuntimeException, which means
you are NOT forced to catch it by the compiler. Please refer to
MalformedCachePatternException for a discussion of when you
should and shouldn't catch this exception.
Parameters: expression The regular expression to fetch from the cache in compiled form.
Returns: The Pattern corresponding to the String representation of the regular expression.
Throws: MalformedCachePatternException If there is an error in compiling the regular expression.
addPattern()
except that it doesn't
throw a MalformedPatternException. If the pattern is not in the
cache, it is compiled, placed in the cache, and returned. If
the pattern cannot be compiled successfully, it
throws a MalformedCachePatternException.
Note that this exception is derived from RuntimeException, which means
you are NOT forced to catch it by the compiler. Please refer to
MalformedCachePatternException for a discussion of when you
should and shouldn't catch this exception.
Parameters: expression The regular expression to fetch from the cache in compiled form. options The compilation options to use when compiling the expression.
Returns: The Pattern corresponding to the String representation of the regular expression.
Throws: MalformedCachePatternException If there is an error in compiling the regular expression.
Returns: The current size of the cache (i.e., the number of elements currently cached).